Can you say "that which" instead of "that that"?
With as much context as you've given, that which is preferable. Of course not every that that can be substituted like this, depending on which that is the conjunction and which is the pronoun.
With as much context as you've given, that which is preferable. Of course not every that that can be substituted like this, depending on which that is the conjunction and which is the pronoun.